c# - Automapper 不忽略嵌套属性

Question

我已经浏览过各种类似的帖子，但无法发现我的方法有这个错误。基本上我有两个 View 更新“设置”对象的不同部分。 View 模型包含两个属性之一，根据设置的属性，应该忽略另一个。当它是 ViewModel ==> Entity direct 时，它工作正常，但是当 Automapper 尝试更新嵌套对象时，它会失败。

我有以下对象结构:

public class Account
{
    public int AccountId { get; set; }
    public DateTime DateToBeIgnored { get; set; }
    public AccountSetting Settings { get; set; }
}

public class AccountSetting
{
    public string PropertyOne { get; set; }
    public string PropertyTwo { get; set; }
}

public class AccountViewModel
{
    public int AccountId { get; set; }
    public DateTime DateToBeIgnored { get; set; }
    public AccountSettingViewModel Settings { get; set; }
}

public class AccountSettingViewModel
{
    public string PropertyTwo { get; set; }
}

public class OtherAccountSettingViewModel
{
    public string PropertyOne { get; set; }
}

通过映射:

void WireUpMappings()
{
    // From the entities to the view models
    Mapper.CreateMap<Account, AccountViewModel>();
    Mapper.CreateMap<AccountSetting, AccountSettingViewModel>();
    Mapper.CreateMap<AccountSetting, OtherAccountSettingViewModel>();

    // From the view models to the entities
    Mapper.CreateMap<AccountViewModel, Account>()
        .ForMember(dest => dest.DateToBeIgnored, opt => opt.Ignore());

    Mapper.CreateMap<AccountSettingViewModel, AccountSetting>()
        .ForMember(dest => dest.PropertyTwo, opt => opt.Ignore());

    Mapper.CreateMap<OtherAccountSettingViewModel, AccountSetting>()
        .ForMember(dest => dest.PropertyOne, opt => opt.Ignore());

    Mapper.AssertConfigurationIsValid();
}

映射 [OtherAccountSettingViewModel --> AccountSetting] 时，仅分配了属性“PropertyTwo”(并且“PropertyOne”的原始值保持不变)-这是我所期望的。

但是，当映射 [AccountViewModel --> Account] 时，“DateToBeIgnored”将按预期被忽略，而 Account.AccountSetting.PropertyTwo 的先前值将替换为“null”。

谁能发现我方法的错误？

Answer 1

解决方法如下:

[TestMethod]
public void TestMethod1()
{
     Mapper.CreateMap<AccountViewModel, Account>()
        .ForMember(dest => dest.DateToBeIgnored, opt => opt.Ignore())
        .ForMember(dest=>dest.Settings, opt=>opt.UseDestinationValue());

    Mapper.CreateMap<AccountSettingViewModel, AccountSetting>()
        .ForMember(dest=>dest.PropertyOne, opt=>opt.Ignore())
        .ForMember(dest => dest.PropertyTwo, opt => opt.MapFrom(a => a.PropertyTwo));

    Mapper.AssertConfigurationIsValid();

    AccountViewModel viewmodel = new AccountViewModel()
    {
        AccountId = 3,
        DateToBeIgnored = DateTime.Now,
        Settings = new AccountSettingViewModel() { PropertyTwo = "AccountSettingViewModelPropTwo" }
    };

    Account account = new Account()
    {
        AccountId = 10,
        DateToBeIgnored = DateTime.Now,
        Settings = new AccountSetting() { PropertyOne = "AccountPropOne", PropertyTwo = "AccountPropTwo" }
    };

    account = Mapper.Map<AccountViewModel, Account>(viewmodel, account);

    Assert.IsNotNull(account);

}